Effect of welding processes on mechanical properties microstructural characteristics and creep resistance of dissimilar 9cr1movnb ferritic martensitic 316l n austenitic stainless steel joints

Abstract

9Cr-1Mo-V-Nb / P91 steel is an acronym for 9 % chromium and 1 % newlinemolybdenum containing ferritic/martensitic steel(F/M). The combination of newlinechromium(Cr) and molybdenum(Mo) improves the swelling resistance, void newlineformation and the presence of major precipitation strengthening micro alloys newline(vanadium(V), niobium (Nb), and nitrogen(N)) enhances the creep resistance newlineand mechanical properties of the 9Cr-1Mo-V-Nb steel. These micro alloys newlineenhance the ductility and reduce the deterioration of the material during longterm newlinetemperature exposure. These 9Cr-1Mo-V-Nb type F/M steels are newlinespecially designed and developed to fabricate the generation IV Fast Breeder newlineReactor (FBR) components. The austenitic type 316L(N) SS is 18Cr- 8Ni on newlineits composition. Because of its superior corrosion and creep resistance in newlinechallenging environments and in high-temperature conditions, it is utilized for newlinefabricating corrosion resistive components in the FBR. 316L(N) SS provides newlinehigh ductility, strength, and fracture toughness in challenging environments newlinelike nuclear reactors and their support structures. In the FBR, 9Cr-1Mo-V-Nb newlinesteel is utilized as the steam generator material, and the 316L(N) is utilized as newlinethe intermediate heat exchanger material. A dissimilar joint is made to newlineconnect the steam generator pipe to the sodium-to-sodium intermediate heat newlineexchanger in the FBR. Fabrication of these dissimilar weld joints(DWJ) is newlinecomplex because of the heterogeneities that occurred due to the differences in newlinephysical and thermal properties of the dissimilar base metals and the filler newlinemetal composition. newline